Create an empty file of certain size

[Mark Dodwell]

Hi,

I need to create an empty (or at least garbage) file of a certain size.
I'm doing it the way below, but it is rather slow -- any ideas on a
quicker way?

File.open("tmp.txt", 'w') { |f| 10.megabytes.times { f.write "a" } }

Thanks!

~ Mark

 

[ara.t.howard]

Hi,

I need to create an empty (or at least garbage) file of a certain
size.
I'm doing it the way below, but it is rather slow -- any ideas on a
quicker way?

File.open("tmp.txt", 'w') { |f| 10.megabytes.times { f.write "a" } }

Thanks!

~ Mark

fd.truncate( 2 ** 20 )

a @ http://codeforpeople.com/

 

[Mark Dodwell]

fd.truncate( 2 ** 20 )

Thanks that's great, didn't know about that method!

 

[Robert Klemme]

Thanks that's great, didn't know about that method!

If it does not work on your platform, you can speed up your solution
by writing larger chunks:

BUFFER = ("a" * 1024).freeze
File.open("tmp.txt", 'wb') { |f| 10.kilobytes.times { f.write BUFFER } }

Kind regards

robert

 

[Heesob Park]

If it does not work on your platform, you can speed up your solution
by writing larger chunks:

BUFFER = ("a" * 1024).freeze
File.open("tmp.txt", 'wb') { |f| 10.kilobytes.times { f.write BUFFER } }

Here is another way:

size = 2**30
File.open("tmp.txt","wb"){|f|f.seek(size-1);f.write("\0")}

Regards,

Park Heesob